My present invention relates to three-dimensional structures of sheet material which may be used as construction toys, to erect displays, for packaging materials and for miniature and full-size construction, to kits from which three-dimensional structures may be created and to a linking system whereby three-dimensional structures be interconnected or parts of a single three-dimensional structure may be connected together.
While this invention may be described in connection with one or more of the uses mentioned and, in particular, as a construction toy, the principles of the invention are applicable widely to three-dimensional structures fabricated from sheet materials generally and can be used in all applications of such materials and in all applications in which three-dimensional structures can be erected from such materials.
The materials with which the invention is intended to be used are sheet materials which have a certain degree of flexibility and can be provided with bends or folds, although aspects of the invention can be used with sheet materials which are practically rigid and in which corners may be formed by providing film hinges or the like. The term xe2x80x9csheet materialxe2x80x9d is therefore intended to encompass both rigid and flexible materials to the extent that they are consistent with the applications described herein. Paper, paperboard, cardboard, laminated papers, plastic sheet, laminates of various plastic and coated paper, paperboard and like materials are those which the invention is principally used.
When reference is made here to construction toys, packaging materials, displays and structures generally, it is by way of example only and features described here, for example, as part of a construction toy, can be used for a display rack or case, for some other kind of structure, not necessarily in a miniature or flimsy form.
Sheet materials have been assembled into utilitarian structures such as boxes and even articles of furniture, have been folded, die cut and connected to other elements by gluing, stapling and even by interlocking tabs, flanges or flaps with slits or slots inside any such sheet material.
In addition, construction toys and the like are known which have slots or slits opening at their edges and which are dimensioned to allow the slits of one piece to be fitted into slits of another and thus multiple pieces are assembled into relatively complex structures. The three-dimensional elements which are so formed can be flat or cylindrical and can be of rectangular, triangular or other polyhedral shapes. It is also known, for example, to thread one strip of sheet material through a slit formed in another to join those sheet material strips in a particular relationship.
While the number of applications that the assembly of sheet material into structures may have is countless and the ways in which sheet materials have been joined is diverse, there remains a need for a simple system for creating three-dimensional effects from sheet material and connecting three-dimensional articles which enables the assembly in a simple manner, is inexpensive and is versatile.
It is, therefore, the principal object of the present invention to provide a construction which satisfies the desiderata mentioned above and which can enable the formation of complex but stable three-dimensional structures starting from sheet material and especially sheet materials which are flexible, bendable and foldable without the drawbacks of earlier systems.
More specifically, it is an object of this invention to provide a three-dimensional structure which is of light weight, is easily assembled, can have its parts made available in a convenient package and is of low cost.
Another object of the invention is to provide a three-dimensional structure of improved versatility.
These objects and others which will become apparent hereinafter are attained, in accordance with the invention, utilizing a system for connecting different elements or parts of the same element and wherein a loop formed on one element or part is inserted through a window formed in another element or part and is held in place by a pin such that all of the components of the structure, namely, the first element or part, the second element or part and the pin are composed of the same sheet material and preferably separated from the same piece of material.
I have found that this is possible by providing the pin as a strip of the sheet material which is folded over and engaged in the aforementioned loop, by pressing the loop out from the sheet material of the first element after the latter has been inside with two parallel slits and by forming the window as a cutout in the sheet material.
The element formed with the lip may be folded or bent into three-dimensional shapes from the sheet material and the opposite edges of that element can be joined together, e.g. by interfitting slits. The pin may be folded into a dihedral form along a score line promoting the folding action and blanks of the sheet material may have two parts separated therefrom along respective score lines.
The loop itself may be formed at a corner of a three-dimensional shape folded from the sheet material and may represent a dihedron where it passes the window.
The three-dimensional element coupled in this manner can be folded from flat blanks to form the three-dimensional shapes and may be interfitted as in a construction toy.